1. Field of the Invention
The present invention belongs to a technical field of vehicle-installed electronic devices and, more specifically, to a technical field of electric power feeding in vehicle-installed electronic devices.
2. Description of the Related Art
In recent years, it has been popularized to install various electronic devices, such as audio devices, video devices and navigation devices, in vehicles. Normally, these electronic devices are each operated by receiving power feeding from a battery provided in a vehicle.
In general, when the power feeding is carried out from the battery to such a vehicle-installed electronic device, the electric power is supplied based on power supply lines of two systems comprised of: an accessory (ACC) power supply in which the electric power is supplied from the battery via a key switch provided in the vehicle; and a backup power supply in which the electric power is constantly supplied from the battery, i.e. not linking to the key switch. The ACC power supply is constituted along with a starter switch for starting an engine and, when an ignition switch or an accessory (ACC) switch turns to ON state, it feeds the electric power to the vehicle-installed electronic device. A schematic structure relating to the power supplies for such a vehicular electronic device is shown in FIG. 9.
An electronic device 10 shown in FIG. 9 is provided with: an ACC power supply monitor section 11 which is connected to an ACC power supply line 3 connected to a battery 1 via a key switch 2 and monitors a state in which the electric power is fed to the ACC power supply line 3 (hereinafter referred to as xe2x80x9cenergized statexe2x80x9d); a central processing unit (hereinafter referred to as xe2x80x9cCPUxe2x80x9d) 15 and a flash memory 16 each connectable to a backup power supply line 4 connected to the battery 1; and a main memory 17 connected to the backup power supply line 4. The CPU 15 and the flash memory 16 are connected to the backup power supply line 4 via control switches 12 and 13, respectively, which are controlled by the ACC power supply monitor section 11.
The ACC power supply monitor section 11 is connected to the backup power supply line 4 and also mutually connected to the CPU 15, and detects the presence/absence of energization in the ACC power supply line 3, thereby to output a result of the detection to the CPU 15.
Specifically, when the energized state of the ACC power supply line 3 is detected, the ACC power supply monitor section 11 turns on the control switches 12 and 13 to connect the backup power supply line 4 to the CPU 15 and the flash memory 16 for energization thereof.
On the other hand, when the ACC power supply monitor section 11 detects a state in which the electric power is not fed to the ACC power supply line 3 (hereinafter referred to as xe2x80x9cinterrupted statexe2x80x9d), it outputs a result of the detection to the CPU 15 when the interrupted state is detected.
After notifying the CPU 15 of the detection of the interrupted state, the ACC power supply monitor section 11 is notified from the CPU 15 that data about operations (hereinafter referred to as xe2x80x9coperation dataxe2x80x9d) has been stored in the main memory 17 (hereinafter referred to as xe2x80x9cOFF processingxe2x80x9d), which will be described later. When the execution of the OFF processing is notified, the ACC power supply monitor section 11 controls the respective control switches 12 and 13 to be turned off, thereby to interrupt the power feeding to the CPU 15 and the flash memory 16.
The CPU 15 controls the flash memory 16 and the main memory 17 based on the presence/absence of energization in the ACC power supply line 3.
Specifically, when the electric power is first fed to the vehicle-installed electronic device 10 after it has been disposed, the CPU 15 controls the flash memory 16 to output operation data such as initial data and operation programs stored therein to the main memory 17. After the operation data has been outputted to the main memory 17, i.e. once the power feeding has been started, even if the power feeding through the ACC power supply line 3 is interrupted, the operation data can be held in the main memory 17 which is constantly supplied with the electric power through the backup power supply line 4. The CPU 15 executes reading of operation data stored in the main memory 17 and writing of operation data into the main memory 17, and further executes a control of respective sections (not shown) which perform navigation and AV operations.
Further, when the power feeding through the ACC power supply line 3 is interrupted, i.e. upon notification of the interrupted state of the ACC power supply line 3 from the ACC power supply monitor section 11, the CPU 15 executes the OFF processing to write the operation data into the main memory 17. After completion of the OFF processing, the CPU 15 notifies the ACC power supply monitor section 11 that the OFF processing has been finished.
The flash memory 16 is comprised of a nonvolatile memory and allows reading and writing of data at low speed. The flash memory 16 stores initial operation data and, upon the first feeding of the electric power, outputs the initial operation data to the main memory 17.
The main memory 17 allows reading and writing of data such as the operation data at high speed. Irrespective of whether the electronic device 10 is operated or not, i.e. even if the power feeding to the ACC power supply monitor section 11 through the ACC power supply line 3 is interrupted, the electric power is constantly supplied to the main memory 17 through the backup power supply line 4.
The power interruption processing of the conventional electronic device 10 having the foregoing structure will be explained hereinbelow.
First, when the ACC power supply monitor section 11 detects the interrupted state of the ACC power supply line 3 due to switching-off, engine stop or the like, this detection result is notified to the CPU 15.
Then, the CPU 15 performs the OFF processing to store the operation data into the main memory 17 and, after completion of the OFF processing, notifies the ACC power supply monitor section 11 that the OFF processing has been executed.
Finally, after the notification of the completion of the OFF processing to the ACC power supply monitor section 11, the ACC power supply monitor section 11 controls the respective control switches 12 and 13 to be turned off, thereby to interrupt the power feeding to the CPU 15 and the flash memory 16.
As described above, according to the conventional electronic device 10, even if the power feeding through the ACC power supply line 3 is interrupted, i.e. even if the operation of the electronic device 10 is stopped, the operation data of the electronic device 10 is not deleted so that the operation data at the time of the interruption of the power feeding can be protected. Thus, when the ACC power supply line 3 is energized thereafter to start operations of the respective sections, the electronic device 10 can be restored to the operation state before the interruption of the power feeding.
However, in these days when environment is seriously considered worldwide to advance energy saving, there has been a problem that the conventional vehicle-installed electronic device consumes energy wastefully.
Specifically, in case of the conventional vehicle-installed electronic device, even if the power feeding to the respective sections such as the CPU is interrupted during an engine being stopped, the backup power supply line is constantly connected to the main memory to keep the power feeding for holding the operation data, thus the power feeding to the vehicle-installed electronic device is not interrupted completely.
For solving such a problem, it may be proposed to unify the power supply lines for power feeding to the vehicle-installed electronic device so as to completely interrupt the power feeding during the engine being stopped. However, according to the existing vehicle-installed electronic device, the backup power supply line is connected to the main memory to keep the power feeding to the main memory for holding the operation data, irrespective of energization of the ACC power supply line. Thus, if a structure without the backup power supply line is adopted, there will arise a problem that it is difficult to hold the operation data.
The present invention has been made in view of the foregoing problems and has an object to provide an electronic device which can back up operation data of the electronic device even when power supply lines for power feeding to the electronic device are unified.
The above object of the present invention can be achieved by an electronic apparatus of the present invention, wherein the electric power is fed thereto from an electric power supply installed in a movable body, and data representing an operation state of the electronic apparatus upon interruption of the power feeding thereto is recorded into a memory device. The electronic apparatus is provided with: an acquiring device for acquiring moving information representing a moving state of the movable body; a predicting device for predicting an occurrence of interruption of the power feeding based on the acquired moving information; and a writing device for writing the data into the memory device when the occurrence of interruption of said power feeding is predicted.
According to this invention, the predicting device predicts the occurrence of interruption of the power feeding based on the acquired moving information, and the writing device writes the data into the memory device when the occurrence of interruption of the power feeding is predicted.
Therefore, since the operation data can be properly stored by predicting the occurrence of interruption of the power feeding, when the electric power is again fed to the electronic apparatus, the operation of the electronic apparatus can be restored without carrying out a bothersome operation such as operation setting for the electronic device.
In one aspect of the present invention, the movable body moves relying on the motive power, and the electric power is fed to the electronic apparatus while the motive power is active; the predicting device predicts stopping of the motive power of the movable body based on the acquired moving information and further predicts the occurrence of interruption of the power feeding by predicting the stopping of the motive power; and the writing device writes the data into the memory device when the stopping of the motive power of the movable body is predicted.
According to this aspect, the predicting device predicts stopping of the motive power of the movable body, and the writing device writes the operation data into the memory device when the stopping of the motive power is predicted.
Therefore, since the operation data can be properly stored by predicting the occurrence of interruption of the power feeding, when the electric power is again fed to the electronic device, the operation of the electronic apparatus can be restored without carrying out a bothersome operation such as operation setting for the electronic apparatus.
In another aspect of the present invention, the moving information includes at least one of stop information, speed information, acceleration information and vibration information of the movable body.
According to this aspect, the stopping of the motive power of the movable body or the power supply interruption can be predicted based on any one of the stop information, the speed information, the acceleration information and the vibration information of the movable body.
In further aspect of the present invention, the moving information is any one of the speed information, the acceleration information and the vibration information and, when a value of the speed information, the acceleration information or the vibration information acquired by the acquiring device is no greater than a predetermined threshold value, the predicting device predicts the occurrence of interruption of the power feeding.
According to this aspect, the predicting device can predict the occurrence of interruption of the power feeding when the value of the speed information, the acceleration information or the vibration information is no greater than the predetermined threshold value.
The above object of the present invention can be achieved by an electronic apparatus of further aspect of the present invention, wherein the electric power is fed thereto from an electric power supply installed in a movable body, and data representing an operation state of the electronic apparatus upon interruption of the power feeding thereto is recorded into a memory device. The electronic apparatus is provided with: a recognizing device for acquiring position information of the movable body to recognize a current position of the movable body; a storing device for storing point information about one or more points registered in advance; a predicting device for predicting an occurrence of interruption of the power feeding when the current position of the movable body is recognized within a preset region from the stored point; and a writing device for writing the data into the memory device when the occurrence of interruption of the power feeding is predicted.
According to this aspect of the present invention, when the current position of the movable body is recognized within the preset region from the point registered in advance, the predicting device predicts the occurrence of interruption of the power feeding, and the writing device writes the data into the memory device.
The probability is high that the movable body is stopped and the interruption of the power feeding to the electronic apparatus is implemented at the registered point.
Therefore, the operation data can be stored by predicting the point where the movable body is stopped and the power feeding is interrupted. Accordingly, the operation data can be properly stored, and thus, when the electric power is again fed to the electronic device, the operation of the electronic device can be restored without carrying out a bothersome operation such as operation setting for the electronic apparatus.
In still further aspect of the present invention, the electronic apparatus performs a route search for the movable body based on information about a destination of the movable body and the recognized current position of the movable body, thereby to set a route to the destination of the movable body; the storing device stores, as the point information, the destination or a stop-by point registered upon setting the route; the predicting device predicts the occurrence of interruption of the power feeding when the current position of the movable body is recognized within the preset region from the stored destination or the stored stand-by point; and the writing device writes the data into the memory device when the occurrence of interruption of the power feeding is predicted.
According to this aspect, the predicting device predicts the occurrence of interruption of the power feeding when the current position of the movable body is recognized within the preset region from the destination or the stand-by point which is set by the route search, and the writing device writes the data into the memory device.
At the destination or the stand-by point, the movable body is stopped and the interruption of the power feeding to the electronic apparatus is implemented.
Therefore, the operation data can be stored by predicting the point where the movable body is stopped and the power feeding is interrupted. Accordingly, the operation data can be properly stored, and thus, when the electric power is again fed to the electronic apparatus, the operation of the electronic apparatus can be restored without carrying out a bothersome operation such as operation setting for the electronic apparatus.
In yet further aspect of the present invention, the electronic apparatus further comprises the memory device comprising a nonvolatile memory.
According to this aspect, the nonvolatile memory is provided, and the writing device writes the data into the nonvolatile memory. Thus, the data can be properly stored when the power supply is interrupted.
The above object of the present invention can be achieved by a data recording method of the present invention in an electronic apparatus, wherein the electric power is fed thereto from an electric power supply installed in a movable body, and data representing an operation state of the electronic apparatus upon interruption of the power feeding thereto is recorded into a memory device. The data recording method of the present invention is provided with: an acquiring process of acquiring moving information of the movable body; a predicting process of predicting an occurrence of interruption of the power feeding based on the acquired moving information; and a writing process of writing the data into the memory device when the occurrence of interruption of the power feeding is predicted.
According to this aspect, the occurrence of interruption of the power feeding is predicted based on the acquired moving information, and the data is written into the memory device when the occurrence of interruption of the power feeding is predicted.
Therefore, since the operation data can be properly stored by predicting the occurrence of interruption of the power feeding, when the electric power is again fed to the electronic apparatus, the operation of the electronic apparatus can be restored without carrying out a bothersome operation such as operation setting for the electronic apparatus.
In one aspect of the present invention, the movable body runs relying on the motive power, and the electric power is fed to the electronic apparatus while the motive power is active; the predicting process predicts stopping of the motive power of the movable body based on the acquired moving information and further predicts the occurrence of interruption of the power feeding by predicting the stopping of the motive power; and the writing process writes said data into the memory device when the predicting process predicts the stopping of the motive power of the movable body.
According to this aspect, the stopping of the motive power of the movable body is predicted, and the operation data is written into the memory device when the stopping of the motive power is predicted.
Therefore, since the operation data can be properly stored by predicting the occurrence of interruption of the power feeding, when the electric power is again fed to the electronic apparatus, the operation of the electronic apparatus can be restored without carrying out a bothersome operation such as operation setting for the electronic apparatus.
In another aspect of the present invention, the moving information includes at least one of stop information, speed information, acceleration information and vibration information of the movable body.
According to this aspect, the stopping of the motive power of the movable body or the power supply interruption can be predicted based on any one of the stop information, the speed information, the acceleration information and the vibration information of the movable body.
The above object of the present invention can be achieved by a data recording method of further aspect of the present invention in an electronic apparatus, wherein the electric power is fed thereto from an electric power supply installed in a movable body, and data representing an operation state of the electronic device upon interruption of the power feeding thereto is recorded into a memory device. The data recording method is provided with: a recognizing process of acquiring position information of the movable body to recognize a current position of the movable body; a predicting process of predicting an occurrence of interruption of the power feeding when the current position of the movable body is recognized within a preset region from point information representing one or more points registered in advance; and a writing process of writing the data into the memory device when the occurrence of interruption of the power feeding is predicted.
According to this aspect of the present invention, when the current position of the movable body is recognized within the preset region from the point registered in advance, the occurrence of interruption of the power feeding is predicted, and the data is written into the memory device.
The probability is high that the movable body is stopped and the interruption of the power feeding to the electronic apparatus is implemented at the registered point.
Therefore, the operation data can be stored by predicting the point where the movable body is stopped and the power feeding is interrupted. Accordingly, the operation data can be properly stored, and thus, when the electric power is again fed to the electronic apparatus, the operation of the electronic apparatus can be restored without carrying out a bothersome operation such as operation setting for the electronic apparatus.
In still further aspect of the present invention, the electronic apparatus performs a route search for the movable body based on information about a destination of the movable body and the recognized current position of the movable body, thereby to set a route to the destination of the movable body; the predicting process predicts the occurrence of interruption of the power feeding when the current position of the movable body is recognized within the preset region from the destination or a stand-by point registered upon setting the route; and the writing process writes the data into the memory device when the occurrence of interruption of the power feeding is predicted.
According to this aspect, the occurrence of interruption of the power feeding is predicted when the current position of the movable body is recognized within the preset region from the destination or the stand-by point which is set by the route search, and the data is written into the memory device.
At the destination or the stand-by point, the movable body is stopped and the interruption of the power feeding to the electronic apparatus is implemented.
Therefore, the operation data can be stored by predicting the point where the movable body is stopped and the power feeding is interrupted. Accordingly, the operation data can be properly stored, and thus, when the electric power is again fed to the electronic apparatus, the operation of the electronic apparatus can be restored without carrying out a bothersome operation such as operation setting for the electronic apparatus.